Assignment Questions

1. What is the difference between pass by reference & pass by pointers?

2. What is the use of the initialization list in the constructor?

3. What is meant by a reference & its advantage?

4. Class has a reference, pointer and a const. Is it possible to write the copy constructor & assignment operator overloading funciton? how?
( Since reference is there, I'm not sure on how to write for it)

5. Example for a variable decleration and definition? (I know for function but for variable don kw how)